Assessing the cost-effectiveness of point-of-care testing for patients
with symptoms suggestive of Acute Coronary Syndrome in primary
care: a threshold analysis
Michelle M.A. Kip, MSc1, Marco J. Moesker, MSc1, Lotte M.G. Steuten, PhD2,3, Ron Kusters, PhD1,4
1University
of Twente, Department of Health Technology and Services Research, MIRA, Enschede, The Netherlands
2PANAXEA b.v., Enschede, The Netherlands
3Fred Hutchinson Cancer Research Center, Hutchinson Institute for Cancer Outcomes Research, Seattle, USA
4Jeroen Bosch Hospital, Laboratory for Clinical Chemistry and Haematology, ’s-Hertogenbosch, The Netherlands
Background
•
•
•
Excluding acute coronary syndrome (ACS) in primary care is a diagnostic challenge for general practitioners (GPs).
Because of the severity of ACS, referral rates to secondary care are high.
• However, in only 14-16% of these patients a cardiac origin is found to cause the symptoms.
This poses a burden on both a hospital’s treatment capacity as well as on the healthcare budget.
Point of care testing (POCT) of cardiac markers might improve the certainty with which ACS can be ruled out at the GP’s office and
reduce referral rates to secondary care.
Objective:
Estimate the minimum sensitivity and specificity of the GP’s clinical assessment combined with POCT (POCT strategy) that is required
to be cost-effective compared to clinical assessment by the GP only (non-POCT strategy).
Methods
A health economic model was developed, investigating the costs and health benefits of the two strategies:
• Data were obtained from the Dutch Healthcare Authority (NZA), the cost manual by Hakkaart-van Roijen, 20101, and from a
systematic search of published medical literature.
• Health benefit was expressed as health-related quality of life, i.e. QALYs.
• Sensitivity and specificity for a GP’s clinical assessment for ACS (non-POCT strategy) is set at 88.3% and 72.2% respectively2.
• Willingness To Pay Threshold: POCT is considered cost-effective when the POCT strategy costs less than €30,000 per QALY
gained compared to the non-POCT strategy.
Threshold analysis:
• Goal: to identify the minimum combinations of sensitivity and specificity that are required for the POCT strategy to be considered
cost-effective compared to the non-POCT strategy.
• Following this, the expected effect of those combinations on health outcomes will be investigated.
Results
Sensitivity POCT strategy
100%
Effect of performance of the POCT strategy on health outcomes (per 100,000 GP consultations).
97%
Performance POCT strategy
94%
91%
Sensitivity 97%, Specificity 95%
Sensitivity 97%, Specificity 75%
Sensitivity 85%, Specificity 70%
Sensitivity 85%, Specificity 89%
non-POCT
strategy
88%
85%
82%
65%
POCT Costs ≤ €30.000
/QALY but results in
QALY gain
POCT saves money and results in QALY gain Findings:
70%
75% 80% 85% 90%
Specificity POCT strategy
95%
100%
Net health benefit. This graph shows the net health benefit for the
POCT strategy compared to the non-POCT strategy. Green indicates
combinations of sensitivity and specificity at which the POCT-strategy
is expected to be cost-effective at a WTP of €30,000/QALY, while red
indicates the
POCT
to be cost-ineffective
this WTP.
POCT
Costsstrategy
> €30.000/QALY
and/or results at
in QALY
loss The
black dot represents the non-POCT strategy (base case).
False-negative
test results
avoided
331
329
-127
-123
False-positive
New heart
Mortality
test results
failure cases
cases avoided
avoided
avoided
21,883
33
69
2,644
33
72
-2,161
-26
-21
16,139
-25
-23
• A higher specificity decreases the number of false-positive test results.
• This is expected to reduce the number of false-positive referrals,
thereby decreasing costs.
• A higher sensitivity might decrease the number of false-negative test results.
• This might prevent inadvertent discharge of patients, thereby
improving the quality of care (QALY gain).
Conclusion and Discussion
The use of a POCT cardiac marker in primary care might:
• Improve both the rule-out and rule-in of ACS at the GP, thereby decreasing referral rates and contribute to decreasing healthcare
costs as well as improving quality of care.
• Additional research is necessary to investigate the subgroup of patients with suspected ACS for which GPs consider POCT cardiac
markers (e.g. troponin) helpful in their clinical decision-making.
References:
1Hakkaart-van Roijen, L., et al. (2010). Handleiding voor kostenonderzoek; Methoden
en standaard kostprijzen voor economische evaluaties in de gezondheidszorg.
Rotterdam, Institute for Medical Technology Assessment, Erasmus University 1-127.
2Nilsson S, Ortoft K, Mölstad S. The accuracy of general practitioners’ clinical
assessment of chest pain patients. Eur J Gen Pract. 2008;14(2):50-5.